1. Technical Field
Embodiments are directed to a dynamic range extending method and apparatus using subsampling.
2. Description of Related Art
One metric of a sensor used in imaging is dynamic range, i.e., a ratio of the largest possible signal to the smallest possible signal that can be generated by the sensor. The largest possible signal is directly proportional to the full well capacity of the pixel. The smallest possible is the noise level when no light is incident on the sensor, i.e., the “noise floor” of the sensor. Imaging systems using sensors having a large dynamic range can record both shadow detail and highlight detail.
There are several known techniques for widening the dynamic range of a sensor, each with its own advantages and drawbacks. One such technique includes image synthesizing using averaging, in which multiple frames are exposed using different integration times, e.g., a long integration time and a short integration time. These frames are then averaged to provide a synthesized image. However, such a technique requires an additional frame memory and an expensive sensor, while providing a low frame rate.